1. Field of the Invention
The invention relates generally to magnetic field sensors and more specifically the detection of whether a non-shielded multi-conductor power cable is energized.
2. Background of the Invention
A sensor may be used to monitor a power cable to detect whether current is flowing in the cable. The sensor may be connected to an alarm which becomes active when either current flows or alternatively when current ceases to flow. For example, a sensor may be used to activate an LED when current is running through the power cable. Alternatively, a sensor may be used to activate an alarm if current is cut from the power cable.
To monitor current flow through the power cable, power first must be disconnected. With power disconnected, a resistive device may be placed in line with or a toroid placed around an electrical conductor in the cable to sense a current flow or a magnetic field. These monitors must break and/or isolate a single conductor from the power cable in order to monitor current through the power cable.
Therefore, a need exists to monitor a power cable without interrupting electrical flow and without breaking the electrical connection.